That's an achievement on top of another — Microsoft had just finished 2018 as the world's valuable company.
Just this past December, Windows 10's market share was at 39.22 percent, slightly higher than Windows 7's 36.9 percent, according to Net Applications. It's a number that's taken Microsoft three years to achieve, and it also goes to show just how popular Windows 7 was and still is.
Windows 10 Overtakes Windows 7
Originally, Microsoft had planned to get Windows 10 running on 1 billion devices within three years of its release. When it saw that Windows Phone was struggling, it realized how much of a tall order its goal is, so it promptly extended the timeline. Microsoft still hasn't reached that goal, it's worth noting. Right now, only 700 million devices are powered by Windows 10, but that's an impressive install base in itself, regardless.
Windows 10 is available on a variety of devices. Beyond PCs, it also works on tablets, some smartphones, and even Xbox One consoles. To get more people to install the OS, Windows aggressively tried all sorts of methods, including making the upgrade free and launching a "PC does what?" campaign.
Windows 7 Is Going Away
Windows 7 remains a popular OS for millions of people, but that might not be for long. Microsoft is scheduled to end its support for the system on January 2020. Business users either have to upgrade to Windows 10 after that or pay for the Extended Security Updates program for Windows 7.
Windows 7 will still work after that period, of course, but regular users simply won't receive any more support, especially all sorts of updates centered on security and performance, after January 2020. It's a bummer, that's for sure, but Microsoft has to look forward, and time spent developing Windows 7 is time taken away toward making Windows 10 even better.
Microsoft has stated that Windows 10 might be the last version of Windows. Number-based versions will apparently come to a halt, so don't expect "Windows 11" anytime soon. Instead, Microsoft plans to treat "Windows 10 as a service," which means Microsoft will pivot to providing more updates, fixes, patches, instead of renewing the entire OS from the ground up for each new era.